Channel formed repeater for rolling mills



1935- N. o. J. ERICSSON 2,050,880

CHANNEL FORMED REPEATER FOR .ROLLING MILLS Filgd April 7, 1934 4 Sheets-Sheet l r/ By: M

HTTORNEY 1936- N. o. J. ERICSSON 2,050,880

CHANNEL FORMED REPEATER FOR ROLLING MILLS Filed April 7, i954 4 Sheets-Sheet. 2

I N VEN 701?: Na: OLov Jipcog /c530 H7 TORNEY Aug. 11, 1936. N. o. J. ERICSSON CHANNEL FORMED REPEATER FOR ROLLING MILLS 4 Sheets-Sheet 5 Filed April 7, 1934 IVILs 01.1w

In I HTTORNEY Aug: 11, 1936. M Q J. E N 2,050,880

CHANNEL FORMED REPEATER FOR ROLLING MILLS 4 Sheets-Sheet 4 Filed April 7, 1934 HTTORNEY Patented Aug. 11, 1936 CHANNEL FORMED REPEATER FOR ROLLING MILLS Nils Olov Jacob Ericsson, Bofors, Sweden Application April 7, 1934, Serial No. 719,483 In Sweden April 8, 1933 22 Claims.

This invention relates to improvements in curved channel-formed repeaters for guiding the fore end of the work when rolling iron, steel or other metals. The invention relates more especially to repeaters for rolling work with rectangular or oval cross-sections, particularly of weak dimensions, which make it necessary to introduce the work between the receiving rolls with the principal axis of its cross-section vertical or nearly vertical, which means that the work during its travel from the delivering to the receiving pair of rolls must be twisted 90. Various of the devices described below may, however, in many cases be used also in connection with repeaters where a twisting of 90 of the work is not necessary, for example when rolling pieces with a square section or other sections.

In repeaters where the work is to be twisted 90, said twisting may be effected either before entering or after leaving the repeater or during the travel of the work through the same. In known repeaters where the twisting is not effected during the travel through the very repeater, the twisting is accomplished by forces acting all around the work when the same is passed through a channel or nozzle provided with curved or helical walls or guide-faces.

Said forcible twisting consumes in the known repeaters a frictional work which amounts to such a great part of the pushing force and energy of motion of the work to be rolled that it has not succeeded to return with safety work of a comparatively thin oval, fiat or similar cross-section, i. e. work of a minor rigidity and mass. In such known repeaters the walls of the same are exposed to a considerable wear, which finally will endanger the completion of the twisting operation.

This invention relates to a repeater, wherein the above mentioned disadvantages are avoided. In the repeater according to the invention the twisting of the work is carried out during its travel through the very repeater and without using any forcibly twisting guide-faces.

The invention is based upon the physical law that a rod exposed to buckling tends to bend itself cross-sectionally in that direction, which of fers the least moment of resistance, i. e. perpendicularly to the principal axis of the cross-section. The twisting 90 of the work when travelling through the channel-formed repeater is effected by letting the channel wall force the work to bend itself sharper and sharper, but at the same time leaving the work liberty to freely adjust itself. On account hereof the work, which has entered the repeater with its principal axis horizontal, will automatically twist itself cross-sectionally so that the principal axis of the crosssection'gradually will approach a vertical position, This is accomplished by giving that wall 5 of the channel-formed repeater which guides the work a curvature in the horizontal plane, which from the receiving to the delivering end has a decreasing, if desired continuously decreasing,

radius of curvature so that the work during its 10 travel through the repeater is exposed to a steadily increasing bending force, the dimensions of the channel being such that the work is allowed to bend itself substantially perpendicularly to the principal axis of its cross-section, 15 thereby automatically turning itself substantially cross-sectionally before the arrival at the outlet end of the repeater.

, In order to accomplish the turning of the work 90 cross-sectionally, the section of passage of the 20 channel must be so wide that the walls of the channel do not prevent the automatic completion of said torsion during the bending of the work. But on the other hand, the section of passage of the channel must not be too wide so that soft 25 hot Work can have an opportunity toform folds or loops in the channel, if the. frictional resistance of the channel is great in relation to the rigidity of the work. To avoid this danger, the inner,

against the centre of curvature turned wall of 30.

the channel is, according to the invention, made adjustable along a more or less long part of its length in relation to the outer guiding stationary wall of the channel so that the section of passage of the'channel can be adjusted in relation to the 35 varying properties of the work. The adjustable Wall may suitably be divided in a number of parts, each one of them being independently adjustable.

In rolling mills of the kind in question, the, feeding velocity of the delivering rolls is generally greater than the feeding velocity of the receiving rolls. On account hereof the bend of the work between the two pairs of rolls begins to be lengthened as soon as the receiving rolls have seized the work. Therefore, the repeater must be so arranged at its receiving end that the work at the first part of the repeater will be free to leave the repeater and form a loop or bend outside thereof. This is also possible by letting the first part of the repeater have only an angular section until the outer guide wall begins, and by letting the first part of the guide wall increase but gradually in height so as to facilitate the exit of the bend or loop from the repeater. This bending outwards must not, however, be effected so readily that the frictional resistance alone of the repeater causes the loop to be bent outwards, while in such a case the fore end of the work would never reach the receiving pair of rolls. On the other hand, the resistance against the looping out of the work must not be so great that the work, after its fore end having been seized, instead is bent towards the interior of the repeater, in which case an eye may easily be formed inside thereof that cannot pass through the narrow outlet opening of the repeater, thereby causing the work to be torn apart.

To safely guide the fore end of the work at the beginning part of the repeater and to give to the bend in that part a suitably adapted resistance against looping out and thereby also a suitable rigidity so that the fore end of the work will be safely seized before the looping out at the inlet end begins, an adjustable guiding device is, according to the invention, arranged at thev inlet end ofthe repeater, said guiding device being adapted to receive and deliver the work to the channel-formed part of the repeater. The guiding device may, for example, be tube-shaped. It is pivotally journalled and is supported by a yielding supporting device with a force that is adjustable and adapted to retain the guiding device in its position directed towards the inlet opening of the channel under counter-action of the frictional resistance in'the channel against the passage of the work. According to the invention, the guiding device is supported by a controlling device, which is adapted to automatically change the position of the guiding device through the action of impulses that are released when the fore end of the work is seized respectively when the Work has passed through the receiving pair of rolls so that in the first case, the guiding device is turned out of the channel allowing the work to form a loop outside of the channel and so that in the second case, the guiding device is returned to the original position ready to receive a new piece of work. The invention also relates to the construction of the devices necessary for guiding the work between the receiving rolls and the automatically acting releasing means which, when the work is seized, efiects the operation of the guiding device at the entrance end of the repeater.

Finally, the invention relates to devices for supporting the whole repeater and for adjusting the distance between its inlet and outlet ends and for the displacement respectively the change of the position of the repeater.

These and further characteristics of the invention will be more closely set forth in connection with the following description of the embodiments of the invention disclosed on the accompanying drawings.

Fig. 1 illustrates diagrammatically a channelformed repeater according to the invention, seen from above.

Fig. 2 shows the repeater in a. side elevation.

Fig. 3 is a section along the line IIIIII in Fig. 1.

Fig. 4 is a section along the line IV-IV in Fig. 1.

Fig. 5 illustrates diagrammatically an assembly of the repeater in relation to the two pairs of rolls and other devices.

Fig. 6 shows a longitudinal section through the inlet end of another embodiment of the repeater together with the guiding and controlling devices.

Fig.7 is a cross-section of the repeater in Fig. 6, and Fig. 8 is a plan view of the same in a longitudinal section along the line VIII-VIII in Fig. 7.

Fig. 9 shows a side elevation of the devices for supporting and displacing the repeater.

Fig. 10 shows on a smaller scale a plan view of the devices in Fig. 9.

Fig. 11 shows a longitudinal section through the outlet end of the repeater, a guide tube, the guide casing with guide jaws and other accessories.

Fig. 12 is a section along the line X[IXII, and Fig. 13 a section along the line X[IIXIII in Fig. 11.

Fig. 14 and Fig. 15 show a longitudinal respectively a. cross-section through a modified embodiment of the operating mechanism of the guide aws. I

The channel-formed repeater according to Figs. 1-4 consists of two curved parts a and b, which at care slidably inserted one in the other so that the distance between the inlet and outlet ends of the repeater can be varied within certain limits. Nearest to the inlet end d, the repeater consists only of an angular beam, which forms the upper and inner walls of the repeater. A distance from the inlet end d an outer wall e begins, which gradually is increased in height and bentover inwards. A certain distance from the beginning of the wall 6, the same has the shape shown in Fig. 3 and is gradually transformed into the shape indicated in Fig. 4. Thus,

the wall e also partly forms a bottom of the channel but leaving an open slot 1.

The radius of curvature of the wall e decreases, if desired continuously, in the longitudinal direction of the repeater, counted from the inlet end so. that the work during its passage through the repeater will automatically turn substantially 90 cross-sectionally as described above, whereby the work when arriving to the outlet end of the channel will have its principal axis positioned substantially vertical. In the neighbourhood of the outlet end the part b' is formed as a conical funnel 9. At the outlet end h the repeater has a closed circumference with a section of passage, which has a shape that substantially agrees with the cross-section of the work but has a somewhat larger size than the latter so that the work without too great resistance will be able to pass through the outlet'opening but at the same time will be prevented from tilting over. The said outlet opening may be formed between two wearing dies it, from which the work continues through the guide tube 1 to the guide casing m, in which the fore end of the work is guided and directed between the rolls. To prevent a quick wearing down of the outlet end of the part b, the wearing dies 70 may consist of steel or chill-hardened cast-iron covered with stellite.

As mentioned above, the parts a. and b are curved along a spiral-shaped line, i. e. the radius of curvature decreases from the inlet end in the direction towards the outlet end.

The work entering the repeater being of an oval, fiat or the like cross-section leaves generally the rolls in a lying position, i. e. with the principal axis of its cross-section in a horizontal or substantially horizontal position. The work is passed into the part a of the repeater, the outer wall e of which guides the work and effects its bending in the repeater. Owing to the fact that the radius of curvature of the repeater or rather of the wall e decreases more and more in the longitudinal direction, the work will during its passage through the repeater be subjected to a steadily increasing bending force, and although the passage through the repeater is wide enough to allow the bending of the work in any direction, the work will, however, as mentioned above, tend to bend itself in that direction which offers the least resistance against the bending, i. e. in a plane perpendicular to the principal axis of the cross-section of the work. Subsequently, the work will gradually raise itself from its lying position and in such a state reach the outlet opening h.

Figs. 5-15 illustrate the further development of the above described repeater with regard to diiferent details.

In Fig. 6, I designates the inlet end of the repeater 4 which, at the beginning, consists of two walls placed in an angle towards each other, namely a top wall 2 and an inner side wall 3. The fore end of the work enters into the inlet end of the channel of the repeater after having passed through a guide I93 of the common type (Fig. 5) arranged in front of the rolls IUI, I92. In the inlet end of the repeater I a guide tube 5 is arranged, into which the work is guided. The guide tube 5 is pivotally journalled in the inlet end of the repeater by means of the shaft 6, and it is suspended by a shaft I, which is journalled in a connecting rod 8, the upper end of which is carried by a shaft, which is journalled in the lower end of a piston rod I0. The piston rod I9 is at its upper end rigidly connected to the piston II, which is displaceable in the cylinder I2. This cylinder is supported by the frame I3, which is rigidly connected with the repeater 4. By means of said frame the repeater is also rigidly secured to the housing of the delivering rolls IOI and I02 by means of the beam I4 and the bolt I5. The piston II rests upon a spring I6, the lower end of which is supported by the adjusting screw I1 by means of which the spring pressure can be adjusted.

Into the screw I! a tube I8 is threaded, which encloses and guides the piston rod I0. The top surface I8a of said tube forms a stop for the piston II. The length of stroke of the piston II can be adjusted independently of the spring pressure by screwing the tube I8 in or out. Into the upper cover I9 of the cylinder I2 a stud 20 is screwed, in which a port 20a is bored, the area of passage of which can be regulated by means of a throttle valve 2I. The stud 20 is also by means of a screw connection 22 connected to a tube 23, by means of which a pressure medium can be conveyed to the cylinder I2 or the latter be brought in communication with the outer air. By the action of the spring I6 the outlet end of the tube 5 is pressed with a certain adjustable force against the topwall of the repeater 4. The outlet end of the tube 5 should enter a distance inside of the beginning edge 24 of the outer wall 25 of the repeater 4, which wall corresponds to the wall 6 in Fig. 1. Said outlet end must of course be entered between the edge 24 and the inner wall 26 of the repeater so that the fore end of the work with safety is entered into the repeater 4.

The main features of the repeater according to Figs. 68 may be substantially in accordance with the embodiment shown in Figs. 1-4 and described above. It differs from the same sube stantially therein that the inner wall 26 of the repeater along a more or less great part of its length is made adjustable so that its distance from the outer guiding wall 25, and thus the width of the slot 29, can be changed and adjusted in accordance with the properties of the work in order to give to the repeater a section of passage that allows the free passage :of the work and its desired free adjustmentwith regard to'the two axis of symmetry of its cross-section but prevents the work from forming folds or loops .if its rigidity owing to high temperature and small dimensions would not be sufilcient to withstand the frictional resistance in the repeater. 1

According to Figs. '7 and 8 the inner Wall 26 consists of angle iron parts 25a, which are displaceably secured to the upper wall 2 of the repeater by means of bolts 21 passing through oblong holes 28 in the wall 2. Fig. 8 discloses how the inner wall 26 is composed of different parts 260. in order to facilitate the adjustability. The fore end 30 of the curved suspended wall of each such part, seen in the directionof motion of the work, is lapping over the rear end 3I of the preceding part so that the work can move freely without danger of being jammed by any edges on the wall. The oblong holes 28 for the bolts 21 through the top wall of the repeater must be parallel with each other in each particular part 26a of the wall. In order to make the inlet end of the repeater 4 more rigid, its inner wall may form an integral part I of the repeater (Fig. 6) to a point somewhat before the outlet end of the tube 5.

Figs. 9 and 10 show the device for suspending the two halves 4 and 32 of the repeater. The receiving end of the latter encloses the delivering end of the former in a sliding connectionso that the distance between the ends of the repeater can be adjusted within certain limits. The two parts may be secured together by means of the screw 33 attached to the end of the part 4 and projecting through a slot 34 in the part 32. Both parts may be suspended in the journal 35 by means of a pin 36 entered through an eye on the screw 31. By means of the rightand leftthreaded nut 38 the screw 3'! is connected to the screw 39, which is rigidly connected to the nut 49. The nut 40 encloses a screw 4I .so as to displace the nut 40 in the guide 42 when the screw M is rotated. In the gable walls 43 of the guide 42 the pins 44 of the screw-4| are journalled. The guide 42 is on its bottom side provided with the slot 45 to. allow free motion of the screw 39. One of the pins 44- is suitably extended to form an attachment for the crank 46. The-upper part of the guide 42 is provided with a sleeve 41, by means of which the cylinder can be suspended on the arm 48, which is secured to the block 49. The block 49 is displaceably supported by the rods 58, which are attached in the frame 5 I. Through the block 49 the screw 52 is passed, the pivot pins 53 of which are journalled in the frame, 5I..- One-of said pins is suitably extended to form' an attachment for the crank 54.

The object and mode of action of the suspending device are the following:-

At change of passes of the rolls the repeater has to be displaced parallel with the centre lines of the rolls. At this occasion also the width of the repeater, i. e. the distance between the inlet and outlet ends of the repeater, usually has to be changed. This change of the width also involves a somewhat changed angle of inclination of the repeater, which change is made possible by the journal 35 being rotatable aboutthe pivot 35. The horizontal lateral displacement of the repeater is readily effected, after loosening the fastening screws I5 (Fig. 6) and 51 (Fig. 11) at the inlet respectively the outlet end of the. re-

peater, by turning the crank 16, if only a short displacement is involved or a displacement of only one of several repeaters suspended by the arm 48 is involved. When a more extended lateral displacement of the repeater along the rolls or a displacement of all the rolls carried by the arm '48 is required, the crank 54 istused. The width of the repeater is adjusted manually, or, after loosening the nut of the screw 33, by means of the crank 46. The level of the repeater is adjusted by means of the rightand left-threaded nut 38.

In the outlet end 55 of the repeater 32 the wearing dies 56 are attached, which correspond to the members It in Fig. I. Said end of the repeater is secured to the outer flange of the roller table 58 (shown in cross-section) by means of the bolt 51, said flange being provided with a slot, in which the bolt 51 can be moved along the roller table, when the bolt is loosened. In the roller table 58 .two further longitudinal slots 59 and 68 are made, the former slot being adapted for guiding the frame 6| of the guide tube holder and to form an opening for its fastening screw 62, and the latter slot being adapted as a guide and opening for the guide casing .63 and its fastening bolt 64. The frame of the guide tube holder is provided with :a shaft 65, which also pivotally supports the U-shaped arm 66, between the shanks of which the clamping shoes 61 and 68 are arranged, between which the guide tube '69 for guiding the work towards the directing members is provided. The lower shoes 6'! are each provided with a pivot pin fitting into a corresponding hole in the lower shank of the arm 66. The clamping shoes 68 each have a hole in their upper surface into which the lower end of the clamping screw 18 fits.

By means of this arrangement the guide tube 69 can be maintained in a stable and secure position. By interchangement of washers H or clamping shoes, tubes of different dimensions can be mounted in the same tube supporting arm 66. The arm 66 is maintained in vertical position by means of the bridge 12, the lower ends of which are inserted in holes 13, bored in the base of the frame 6| (Fig. 12).

After lifting the bridge 12, the guide tube 69 may obviously be swung sidewards and downwards, leaving place for removing and interchanging the guide jaws M and 15, without loosening any screw connections.

The cross-section of the tube 69 is formed in accordance with the cross-section of the work, but is of so much larger interior dimensions that the work freely can pass through without being tilted. For oval or similar section of the work lying edgewise, an oval cross-section of the tube is suitable. For a square section of the tube, the section of the tube should be square and so on.

The guide jaws 14 and 15 are divided along the horizontal planeinsteadof the vertical plane as hitherto has been usual. The groove of the lower guide jaw 14 for the work to be rolled should in the part nearest to the rolls have a depth equal to substantially half of the height of the work. The depth of the corresponding groove in the upper guide jaw 75 should be less than half of the height of the work (Fig. 13). The upper surface "16 of the upper guide jaw 15 converges towards the contact edges 1.1 of the jaws. The contact edges '78 of the upper guide jaw are nearest to the outlet end of the guide tube 69 curved as a circle, which touches the edges 11 and has its center located on the'fiange edge 18, about which the upper guide jaw can be pivoted. The J'aw holder 80, the inner surfaces of which are parallel and enclose the pair of jaws in a sliding engagement, allows the upper guide jaw to be raised somewhat with the edge 19 as a pivot.

In the upper part of the jaw holder 88 a lever 8| is pivotally journalled about the shaft 82. By means of a spring 83 the lever is pressed against the upper surface 16 of the jaw 15 with the projection 84, preferably adjustable, of its shorter arm. The uttermost end of its longer arm is widened to a plate 85, against which the spindle of a valve 86 is resting, which is arranged in the guide case 63, wherein the jaw holder 80 is inserted in a horizontal sliding engagement. The jaw holder 80 is adjustable in the horizontal direction by means of the screws 81. The spring 88, being adjustable by means of the screw 89, is intended to give the valve 86 a quick start when the lever plate 85 is moved downwards.

To the interior of the valve casing ports 98, 9| and 92 are leading, whereof port 98 connects the valve casing with the atmosphere, and port 9| with the conduit 23, which leads to the control cylinder |2 in Fig. 5. By means of the tube 93 and the port 92 the valve casing is connected with a source of compressed air. V

If the fore end of the upper guide jaw (nearest to the rolls) is raised, for example owing to the entrance of the work in the pass between the jaws, the projection 84 is moved upwards and the lever end 85 downwards. At the same time the spring 83 is compressed, and the projection 84 exerts a certain pressure downwards upon the guide jaw, which thus is kept pressed towards the Work for a guiding purpose. The force of the spring 83 together with the weight of the upper jaw must not, however, be so great that the work is not allowed to pass freely between the guide jaws to be seized by the rolls.

The above described arrangement acts in the following way:-

When the fore end of the work has passed through the wearing jaws 56 and the guide tube 6| and arrived between the guide jaws 14 and 1-5, the fore part of the upper guide jaw 75 will be raised somewhat owing to the reduced depth of the groove therein, whereby the jaw 15 is pivoted about the edge 19 and the circular edge 18 rolls or slides on its support. Up to this moment the lever 8| and the valve 86 have occupied the positions shown in Figs. 9 and 10, i. e. the control cylinder 2 (Fig. 6) has by way of the conduit 23, the port 9!, the casing of the valve 86 and the port 90 been in connection with the atmosphere. The guide tube 5 has thus been kept in the position shown in Fig. 6 by the pressure of the spring l6, preventing the work to leave the repeater below the edge 24. As the free area of passage in the repeater by adjustment of the rear wall 26 can be made so narrow that the work is prevented from forming folds or loops therein, the fore end of the work is driven forwards with a pushing force, which is determined by the pressure of the spring i6, the highest limit of which is equal to the force that is required for upsetting the work, i. e. thickening the work cross-sectionally. The pushing force can thus be given a value that is quite sufficient to secure the raising of the upper guide jaw 15, as the end of the work is pressed against the jaw with a comparatively small wedge angle.

As soon as the upper guide jaw 15 is raised, the lever 8| is put in motion and its rear end is lowered, releasing the valve 86 to occupy its lower work even when rolling difficult profiles.

position by action of the spring 88. The communication of the valve casing with the atmosphere through the port 90 is now broken off, and the conduit 23 is now instead connected with the compressed air conduit 93 by way of the ports 9| and 92 so that compressed air is led to the cylinder l2 (Fig. 6) above the piston H, the diameter of which should be so great that the pressure of the spring 56 is overcome. Thus, the piston will be moved downwards, until it is stopped by the stop 18a. By means of the piston rod l9 and the connecting rod 8 the guide tube 5 is now pivoted downwards about the shaft 6 to a lowered position that corresponds to the length of stroke of the piston previously adjusted. From now on the work is forced out below the edge 24, especially if the shaft 6 is obliquely journalled so that the outlet end of the tube obtains an oblique motion downwards and outwards. In this way the work is safely moved out of the repeater during the downward motion of the piston II. To prevent the beginning of this motion before the receiving rolls have seized the work, a throttle valve'2l (Fig. 6) is so adjusted that the air flow to the cylinder I2 is retarded in a certain degree.

As soon as the last end of the work has passed the guide jaws l4, 15, the upper guide jaw 15 is returned to its lower position in Fig. 11, partly on account of its weight, partly owing to the action of the spring 83. At the same time, the valve 86 is raised to its upper position, the conduit 93 from the compressed air source is closed, and the conduit 23 is connected with the atmosphere by way of the ports 9! and 99 in the valve casing. The air in the cylinder l2 rushes out, the pressure in the cylinder falls, and the spring l8 returns the piston H and thus also the guide tube 5 to their upper positions, whereupon the repeater again is ready to receive a new piece of work.

The pressure exerted by the upper guide jaw ought to be sufiicient in most cases for a correct guiding of the work during its continued travel between the guide jaws, but if, at the rolling of certain difiicult profiles, it has proved desirable to obtain a greater pressure from the upper guide jaw, after the rolls have seized the work, a modifled device as shown in Figs. 14 and 15 can be used.

This embodiment differs from the above described one therein that between the valve 86 and the rolls a cylinder 94 with a piston 95 carried by a spring 99 have been arranged. The cylinder 9 is above the piston 95 connected with the port 9% by way of the ports 91, 98 and 99. In the port 98 a throttle valve I99 is inserted, whereby the air fiow to the cylinder 94 can be retarded, until the work with safety has been seized by the rolls. At the same time as connection is made between the compressed air conduit 93 and the conduit 23, compressed air enters the cylinder 99 by way of the ports 91, 98 and 99 so that the piston 95 with its piston rod 95a is pressed downwards towards the upper guide jaw 15 with a velocity depending upon the adjustment of the throttle valve. This adjustment is so selected that the pressure on the piston 95 cannot overcome the counter-pressure of the spring 95 until the rolls have securely seized the work. Thereupon the piston rod 95a is pressed towards the upper guide jaw 75 with full force so that said jaw with a sufficient force will be pressed against the work to ensure the correct guiding of the When the work has left the guide jaws, the compressed air rushes out above the piston 95 by way of the ports 99, 98, 91 and 99 into theratmosphere so that the spring 96 can return the piston 95 to its upper position.

The pressure medium may of course be another than compressed air. Any compressed gas or steam can be used, if it works quickly. Electric current may also be used for the operation of the guide tube 5, in which case the valve 86 is replaced .by an electric contact, and the control device of the guide tube 5 with an electromagnet or other electric device.

Further it is not necessary to have the outlet end of the repeater turned downwards. It may also be turned upwards, in which case the construction will be substantially the same although reversed.

By the present invention a direct automatic returning of the fore end of the work from one pair of rolls to a following one is rendered possible also when the cross-section is small in relation to the path of return. Owing to the character of the arrangement the return motion is effected in such a way that a sufficient pushing force is obtained to ensure that the following pair of rolls will safely seize the work before the same has any possibility of leaving the repeater. In difference to the case with hitherto known repeaters the looping out of the work is effected automatically by mechanical means immediately after the rolls of the following pair having seized the work. The devices are thus in a high degree independent of the dimensions of the work to be rolled, its quality and temperature, i. e. its rigidity, and they therefore make an automatic returning possible of much weaker work than hitherto has been possible.

In such cases when it is desired to divide the pushing force in a returning force and a feeding force to the second pair of rolls, or when for some reason the work is allowed to loop out of the repeater after the motion through the repeater, the latter may with advantage be combined with a mechanically working feeding apparatus. This should then be placed between the outlet end 55 of the repeater and the rolls, and the guide casing 63 be replaced by a hitherto used guide casing with guide jaws. The guide tube 59 with its holder will of course not be necessary in such a case. The conduit 23 to the operating device of the guide in Fig. 6 is then connected to the control valve casing of the feeding apparatus if compressed air, gas or steam is used. If electric current is used, the control device of the repeater is completed with the control device of the feeding apparatus so that the work leaves the repeater simultaneously with the start of the feeding apparatus.

Having now particularly described the nature of my invention and the manner of its operation, what I claim is:

1. A channel-formed repeater for rolling mills provided with an outer curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, and wherein at least a part of an inner wall of the repeater is adjustable with regard to the distance between said walls.

2. A channel-formed repeater for rolling mills provided with an outer curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, and wherein an inner wall of the repeater is divided in a number of parts,

each one of which is adjustable with regard to its distance from the outer wall.

3. A channel-formed repeater for rolling mills provided with an outer curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, and wherein an inner wall of the repeater is divided in a number of parts, each one of which is adjustable with regard to its distance from the outer wall, said adjustable parts being provided with a flange, which is attached to the top wall of the repeater by means of bolts passing through oblong holes in the top wall or said flange.

4. A channel-formed repeater for rolling mills provided with an outer curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, and wherein an inner wall of the repeater is divided in a number of parts, each one of which is adjustable with regard to its distance from the outer wall, the ends of said adjustable parts being arranged to overlap each other so as to avoid the formation of edges apt to form obstacles to the passage of the work.

5. A channel-formed repeater for rolling mills provided with a curved guidewall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, a guiding device for the work being arranged at the inlet end of the repeater, which guiding device consists of a tube pivotally journalled at the inlet end of the repeater and supported by a yielding, adjustable force, said inlet end consisting of only two walls positioned in an angle towards each other, the outlet end of the tube being arranged somewhat inside of a point where an outer guide wall of the repeater begins.

6. A channel-formed repeater for rolling mills provided with a curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to the outlet end of the repeater, a guiding device for the work being arranged at the inlet end of the repeater, said guiding device being suspended in a control device adapted to automatically change the position of the guiding device through the action of impulses, which are released when the fore end of the work is seized by the next pair of rolls and when the work has passed said rolls, in such a way that in the former case the guiding device is moved out of the repeater to allow the work to form a bend outside of the repeater, and in the latter case to return the guiding device to its former position to receive a new piece of work.

7. A channel-formed repeater for rolling mills provided with a curved guide wall for the work, the radius of curvature of which decreases in the direction from the inlet end to. the outlet end of the repeater, a guiding device for the work arranged at the inlet end of the repeater and consisting of a tube pivotally journalled at the inlet end of the repeater, said tube being suspended by a piston, displaceably arranged in a cylinder, which alternately is filled with a pressure medium when the work is seized by the next pair of rolls and put in communication with the atmosphere through the action of impulses released when the work has passed the said pair of rolls so that, in the former case the piston turns the tube out of the repeater in counteraction to a spring acting upon the piston, and in the latter case said spring returns the tube to its former position.

8. A repeater as claimed in claim 7, and wherein the length of stroke of said'piston is adjustable by means of an adjustable stop, to enable ing mills combined with two cooperating guide 0 jaws arranged in front of the receiving rolls and adapted to guide the work coming from the repeater, one of said guide jaws being pivotally arranged and adapted to be pivoted by the arriv-- ing work in counter-action of a spring, so that 15':

said pivotable jaw will exert a pressure upon the work, the said jaw being combined with a control device, which at the said motion of the jaw releases an impulse by means of which another control device is activated to operate a guiding 20 device for the work arranged at the inlet end of the repeater so as to allow the work to form a loop outside of the same during the passage of the work through the second pair of rolls.

11. A repeater as claimed in claim 10, and wherein the contact edges of the guide jaws are arranged in the horizontal plane, the upper guide jaw being arranged to be pivoted upwards by the action of the work to release said impulse.

12. A repeater as claimed in claim 10, and 30 wherein a guide tube is arranged between the outlet end of the repeater and the guide jaws, said tube having a closed circumference and a cross-section adapted to prevent the tilting of the Work, the tube being carried on a support piv- 35 otally connected to the frame to enable said guide tube to be swung aside when the guide jaws are to be replaced.

13. A repeater as claimed in claim 10, and wherein a guide tube is arranged between the out- 40 let end of the repeater and the guide jaws, said tube having a closed circumference and a crosssection adapted to prevent the tilting of the work, the tube being carried on a support pivotally connected to the frame to enable said guide tube to 5 be swung aside when the guide jaws are to be replaced, the guide tube being held in correct position for the rolling operation by means of a bridge detachably connected to a support, the bridge being provided with shanks on each side 50 of the guide tube.

.14. A repeater as claimed in claim 10, provided with a guide casing for the guide jaws,

a valve casing arranged in said guide casing, said valve casing being connected, firstly to an admis- 55 sion conduit 'for pressure medium, secondly to a conduit leading to the control device for the guiding device at the inlet end of the repeater, and thirdly to a port leading to the atmosphere, said ports being controlled by a. valve adapted to be 0 operated at the motions of the upper guide jaw at the passage of the work, so that the valve connects said control device at the inlet end of the repeater with the compressed medium conduit respectively the atmosphere. as

15. A repeater as claimed in claim 10, provided with an electric contact device, arranged to control an electric circuit through the motions of the upper guide jaw, said circuit containing an electro-magnetic or other electric member adapted to operate the control device at the inlet end of the repeater.

16. A repeater as claimed in claim 10, provided with a guide casing for the guide jaws, a valve casing arranged in said guide casing, said valve casing being connected, firstly to an admission conduit for pressure medium, secondly to a conduit leading to the control device for the guiding device at the inlet end of the repeater, and thirdly to a port leading to the atmosphere, said ports being controlled by a valve adapted to be operated at the motions of the upper guide jaw at the passage of the work, so that the valve connects said control device at the inlet end of the repeater with the compressed medium conduit respectively the atmosphere, a piston being arranged in a bore in the guide casing, said bore communicating with the valve casing so that when the upper guide jaw is turned upwards, pressure medium is conveyed to the bore, preferably over a retarding valve, to act upon the piston in counter-action to a spring so that a piston rod is pressed against the upper guide jaw to increase the pressure on the work executed by said jaw.

17. A repeater as claimed in claim 10, and wherein the guide jaws are enclosed by a box, which allows the upper guide jaw to be raised vertically by the work and guide the same.

18. A repeater as claimed in claim 10, and wherein the guide jaws are enclosed by a box, which allows the upper guide jaw to be raised vertically by the work and guide the same, said box being adjustably arranged in the guide casing.

19. A repeater as claimed in claim 6, and wherein said control device is provided with electromagnetic means for moving the guiding device out of the repeater, said electromagnetic means being connected to an electric circuit provided with a contact device adapted alternately to close and open said circuit through the action of said impulses.

20. A repeater as claimed in claim 6, and wherein said control device is provided with electromagnetic means for moving the guiding device out of the repeater, said electromagnetic means being connected to an electric circuit provided with a contact device adapted to alternately close and open said circuit through the action of said impulses, and wherein an adjustable retarding device is provided, by means of which the operation of said electromagnetic means to change the position of the guiding device can be retarded more or less after the release of said impulses.

21. A curved channel-formed repeater for rolling mills combined with a vertically displaceable shaft, by which the repeater is pivotally suspended, a nut suspending said shaft and the repeater, a horizontal supporting guide for said nut, a horizontal arm supporting said guide and directed substantially at right angles to the centre lines of the rolls of the rolling mill, and a screw engaging said nut and adapted to displace the nut along said guide for the purpose of displacing the repeater.

22. A repeater as claimed in claim 21, and combined with a guiding member secured to said horizontal supporting arm, means for slidingly supporting said guiding member so as to allow it to be displaced horizontally and parallel with the centre lines of the rolls, said guiding member being adapted as a nut engaging a screw adapted to efiect said displacement of said guiding member.

NILS OLOV JACOB ERICSSON. 

